粳稻亲本选配与杂种后代遗传变异分析

利用稻米直链淀粉含量相近的 6个粳稻品种 ,以 Griffing双列杂交方法 4配制 15个杂交组合 ,对亲本选配与 F2 、 F3籽粒直链淀粉含量的遗传变异特点进行了分析。结果表明 ,大部分组合的 F2 、 F3籽粒直链淀粉含量平均值与亲本平均值差异不大 ,中亲值与 F2 籽粒直链淀粉含量平均值间相关不显著 ,而与 F3籽粒直链淀粉含量平均值呈显著的正相关 ;F2 籽粒直链淀粉含量平均值与 F3籽粒直链淀粉含量平均值间以及 F2 籽粒直链淀粉含量方差与 F3籽粒直链淀粉含量方差之间相关均不显著 ;15个组合 F2 及 F3籽粒直链淀粉含量均呈单峰分布 ,并出现超亲变异 ,直链淀粉含量相近的低直链淀粉含量粳稻品种间无主效基因的差异 ,直链淀粉含量的遗传主要受微效多基因的控制

Analysis on the selection of crossing parents and the genetic variation of the progenies in japonica rice

The selection of crossing parents and the natures of genetic variation of F 2 and F 3 were analysised in the grain amylose content from 15 cross combinations based on the diallel crossing system 4 of Griffing with 6 Japonica rice varieties in the similar content.The results showed that there were not significant differences in the grain amylose content average between F 2,F 3 and parents in the most cross combinations,and the correlation of the midparent value was not significant with the average of F 2 and was positively significant with the average of F 3.There was not significant relationship in the grain amylose content both between the F 2 and F 3 average and between F 2 and F 3 variance.The grain amylose content of F 2 and F 3 of 15 cross combinations all appeared the unimodal distribution and had overparent variation.There was not main gene among the Japonica rice varieties of low and similar grain amylose content.The heredity of grain amylose content was mainly controlled by multimicro genes.